The invention relates to a device for projecting television pictures, provided with a light source and dichroic mirrors which separate the light into three channels, the light being guided through an LCD in each channel, after which the light transmitted by the LCDs in the different channels is united by means of dichroic mirrors into a single channel to be supplied to a projection system.
TV projection systems are in development in which the light coming from a light source is separated into different colour components, such a red, green and blue, in three separate channels by means of dichroic mirrors.
The light beams of different colours running in different channels and obtained in this way are then conducted through liquid crystal display units having two polaroids (referred to as LCDs hereinafter), which are known per se. The LCDs are controlled by control means which are known per se, which are immaterial to the invention, and which will therefore not be described any further, in such a way that only desired portions of the light beams are transmitted in the various channels to form, for example, monochrome components of a color image. The light beams thus transmitted by the LCDs are merged together again by means of dichroic mirrors into a single channel, and the combined light beam thus obtained is eventually fed to a projection system for projecting the desired picture.
The LCDs are generally mounted to a common support member or housing in which the dichroic mirrors used for combining the light beams are also positioned.